GenbankFormat changes to allow reading of Ensembl Genbank files

The existing GenbankFormat has not been able to read Ensembl Genbank files for a while. Part of the problem was db_xrefs that crossed over to the next line.  The other issue was that it was still reading and processing the symbol list even though elideSymbols was set.  These changes will allow for one to be able to read these files but they also require a bit of memory so I'm not sure you want to take the test cases.